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<html lang="en">
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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        li {
            width: 24px;
            height: 24px;
            margin: 24px;
            background-color: pink;
            list-style: none;
            background: url('img/jlt.png') no-repeat;
        }
    </style>
</head>
<body>
    <div>
        <ul>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
        </ul>
    </div>
    <script>
        var lis = document.querySelectorAll('li');
        for(var i = 0; i < lis.length; i++) {
            var index = i*44;
            lis[i].style.backgroundPosition = '0 -' + index + 'px';
        }
    </script>
</body>
</html>